Question

A protein that fits into the cell membrane Select one: a. floats in the cell membrane. b. has a nonpolar middle section. c. has two polar ends that are attracted to water. d. All of the above

Answer 1

Answer: B).has a nonpolar middle section

Explanation: Proteins that fit into the membrane are called integral membrane proteins. These proteins contain nonpolar segment that is made up of hydrophobic amino acids residues which associate with the fatty acyl groups of themethe membrane lipid bilayer through hydrophobic interactions, thereby anchoring the protein to the membrane.

Answer 2

Answer: B

Step-by-step explanation:

Integral membrane proteins, are deeply embedded in the bilayers and are attached by hydrophobic bonds or van see Waals forces. The hydrophobic side chains of the amino acid are embedded in the non-polar hydrophobic central core of the phospholipid membrane. In other words integral proteins contain residues with hydrophobic side chains that interact with fatty acyl groups of the core of the membrane, this interactions forms a bond and anchors the protein to the membrane.